This program is involved with the determination of isoenzyme patterns in serum, urine, and tissue of human patients with breast tumors. The scheduled work goal for the coming year will include serum, urine, and breast tissue collection from patients with benign and malignant breast tumors. Samples will also be collected from females without breast disease for comparison. The isoenzymes of lactic dehydrogenase and malic dehydrogenase will be assayed by agar gel electrophoresis. The resultant isoenzyme patterns will be evaluated by visual observation and densitometry. In addition, tissue protein, DNA, and histochemical isoenzyme localization will be done as well as histologic classification. Comparisons will be made between the isoenzyme patterns of normal sera, urine, and breast tissue, and benign and malignant samples from diseased patients. In addition, the above measures will be made postoperatively in patients to monitor further alterations that may give indications as to response to therapy, disease recurrence, etc.